pappy92651

My X pipe install took about 3 hours. I followed Louie's recommendations and the results were very good. I will try to get the car on the dyno next week for final tuning. The system behind my X pipe uses dual 2.5" pipes, Random Tech 702500 CATs, and DynoMax 17219 mufflers. I installed the Perfect Power SMT-6 computer to control fuel and ignition timing. The car is quiet until about 4000 RPM. At WOT everyone knows where you are. At cruising speeds (below 2500 RPM) the car is quiet. At WOT it is definitely loud and sounds great. The car feels like it has alot more HP. I had to turn my fuel up quite a bit. Total cost was about $1400.00 (Add $300.00 for the SMT-6).

A few people asked me if the X pipe would provide a guaranteed 30 rwhp gain. The answer is no. The combination that makes this level of power uses GT cams, dual 2.5" pipes, Random Tech CATs, high flow mufflers, and more fuel (RRFPR or computer). You can get even more HP by adding a computer which controls the fuel and ignition timing. Louie's GT was making 342 rwhp = 60 HP gain over stock.

Louie shared quite a bit of data on configurations. A few people who had installed just the X pipes saw marginal power increases. Some of the GTS cars with GT cams also saw less than expected power gains. The cars that acheived the highest gains all had completely new exhausts, GT cams, and custom engine management systems. The X pipe will produce power gains. Big power gains require more than just the X pipe. Food for thought.

drnick

nice mods! i cant wait to get my GTS engine installed in my 86, mated up to the ott x and 2.5" pipes.

Chris Lockhart

Sounds great Pappy. Hope you get the #'s you're looking for on the dyno.

How easy is it to install the SMT-6??? I've been thinking about getting one from Louie for awhile now, but was waiting till he perfected the install. TIA,

Steve Cattaneo

Hi Steve, thanks for the card and picture, I am happy to hear you’re on the road again. Those AMG planetary should hold up.

pappy92651

nick, you will be happy with the power gain. It is hard to explain. The engine pulls hard through the entire rpm range, and even harder near red line. The car now snaps my head back when I hit third (auto trans). The 285/30-18s spin hard if I go WOT from a standing start.

Chris, It was not hard to install. On a scale of 0 to 10 it was a 3.5. I used a thermal stripper to expose the wires near the ECU connector after unwrapping the friction tape. I soldered each connection permanently and then wrapped each junction with friction tape. After that I wrapped the whole thing back up. Instructions come with the SMT-6. Louie programs the SMT-6 with the stock S4 maps as a baseline and the image is on a CD that he supplies. The software is highly intuitive. I have not changed my timing yet. WOT is set to give me an AFR of about 13.5:1. This seems to be optimum for the 32V 928 at WOT. Low RPM is at about 16:1 AFR. I may increase the off idle fuel depending on my timing results. The SMT-6 logs your results as you drive. The unit has a molex plug so you can disconnect it instantly from the LH wiring. I have mine mounted under the passenger side tray.

Hello Steve, Good to hear from you. It is nice to know that I have the best hard parts that money can buy. The bill came to about $7000.00 and the transmission shop ate $4000.00 of it because they did not check the planetary assembly for wear. The new setup has all new AMG hard parts and Amsoil fluid with a separate oil cooler. I blew the planetary assy, output shaft, and a clutch drum. One of the planet gears is embedded in the carrier. Nice coffee table piece.

Steve Cattaneo

No, not again?

928ntslow

Steve. Great info to know as that is the route I am headed. I just dynoed the GTS yesterday and came up with stock numbers of 280.7 hp at the rear wheels and 282.0 of torque. A ridiculous amount better than the 82 would ever make.

Where did you get the GT cams?

Rich9928p

Keith, my '93 GTS dyno'd 280.1 RWHP and 291.5 lb-ft. torque, and this is from an A/T. So we're pretty close.

pappy92651

Hello Keith, Mark Hergesheimer found my cams. Greg Brown also has a line on them. I'm sure that a few other folks on the list also have them for sale. They typically run $800.00 a piece new. If your engine has low milage you might be able to do the cam swap without replacing valve lifters, seals, and guides. Be sure to replace the cam oil galley seals / pins at the rear of the head when you do the job. This step is often over looked resulting in low oil pressure after the cams are installed.

280 rwhp sounds healthy! A GTS engine with GT cams, custom exhaust, and custom fuel map can produce better than 340 rwhp. Before the X pipe was installed my car dynoed at 306 rwhp.

Once I get my X pipe dialed in I will be installing the new intake. My torque curve should be enhanced again. I have so many mods on this car that I have to look at my log to know where I'm at. Once upon a time I owned a quiet little S4 that always started off gently in 2nd gear and never spun the rear wheels. Cops ignored me. Now I own a snarling beast.

pappy92651

BTW: Your GTS looks clean! So modern compared to my S4 lines.

928ntslow

Thanks for the info and tips Steve! Your car looks awesome and hopefully I can get a look at it in person one of these days. Your work is certainly paying off and paving the way for other cars to follow.

I have done a few minor cosmetic mods to the GTS which does give a bit more of a contemporary look. The cam and exhaust mods will give me all I think I will want as far as the engine goes. As they say though. it's never enough!

Lagavulin

Congrats on your install!

Can you provide more details on this new intake?

Looking forward to seeing your dyno results.

Normy

Where did you pick up those cats, and how much did they cost, if I might ask?

N-

pappy92651

Hello Lagavulin,

The new intake is a reworked GT intake with 3/8" aluminum side plate spacers. Marc Thomas is / was running a similar configuration. The ports have been cleaned up and textured, not extrude honed (which is reported not to work). After that the surfaces were ceramic coated and fired at 500F for 1 hour. I did this mainly because bare magnesium needs to be coated. The ceramic coating may give me a thermal advantage at low speeds (stop light to stop light) where the manifold tends to heat soak. I'm getting good results with the thermal barriers on the air box, intake tubes, and radiator shield. I dropped the air box temp by 40F at low speed. No more detonation at launch. I am building a polycarbonate deflector which will eliminate rising heat from entering the air tubes at idle with the fans off. I decided not to go with a nose scoop for now. Pressure off the nose of the car is higher than at the front of the hood unless the scoop is high enough to catch clean air.

The intake side plate spacers reduce restriction to the velocity tubes. Marc has proven that this change allows his stroker to make more HP with a wider torque curve. If you look at the interior you immediately see that some of the velocity tubes are in the shadow of others forcing the air to go around the inner tubes. There is a debate about whether the flared part of the tube actually does any good. If I had another manifold I would be tempted to machine them down and radius the inlets. The stock manifold is definitely a restriction.

Lagavulin

Thank you for the detailed post!